Using TypeOf?

[Leon]

I have a program that fill 6 textbox on button click, but when using TypeOf
my program is trying to also fill label controls which throws my array out
of range. how can use TypeOf to only read textbox Control?

Piece of Code:

Dim I As Integer

For I = 0 To Me.Controls.Cou nt - 1

If (TypeOf Controls(I) Is TextBox) Then

Dim tbox As TextBox = CType(Controls( I), TextBox)

tbox.Text = arr1(I)

End If

Next

[Henri]

It's not a matter of TypeOf, it's the way you're using "i" that is wrong:

Dim i As Integer = 0

For j As Integer = 0 To Controls.Count - 1
Dim ctrl As Control = Controls(j)
If TypeOf ctrl Is TextBox Then

DirectCast(ctrl , TextBox).Text = arr1(i)

i += 1

End If

Next
"Leon" <vn*****@msn.co m> a écrit dans le message de
news:eR******** ******@TK2MSFTN GP10.phx.gbl...

I have a program that fill 6 textbox on button click, but when using TypeOf my program is trying to also fill label controls which throws my array out
of range. how can use TypeOf to only read textbox Control?

Piece of Code:

Dim I As Integer

For I = 0 To Me.Controls.Cou nt - 1

If (TypeOf Controls(I) Is TextBox) Then

Dim tbox As TextBox = CType(Controls( I), TextBox)

tbox.Text = arr1(I)

End If

Next

[Henri]

Better:

Dim i As Integer = 0

For Each ctrl As Control In Controls

If TypeOf ctrl Is TextBox Then

DirectCast(ctrl , TextBox).Text = arr1(i)

i += 1

End If

Next

[Leon]

Thanks So Much Henri,
That most definitely solve my problem. Could you please explain to me in
details what I was doing wrong.
Thanks again!

"Henri" <hm********@hot mail.com> wrote in message
news:OC******** ******@TK2MSFTN GP12.phx.gbl...

Better:

Dim i As Integer = 0

For Each ctrl As Control In Controls

If TypeOf ctrl Is TextBox Then

DirectCast(ctrl , TextBox).Text = arr1(i)

i += 1

End If

Next

[Henri]

Ok, imagine that you have to simplify 1 textbox, 1 label, then 1 textbox in
your Controls collection.
arr1's length should be 2 if it's the same as the number of textboxes.

Your code:

Dim I As Integer
For I = 0 To Me.Controls.Cou nt - 1
If (TypeOf Controls(I) Is TextBox) Then
Dim tbox As TextBox = CType(Controls( I), TextBox)
tbox.Text = arr1(I)
End If
Next

Let's trace the for...next loop in your code:

first iteration:
i = 0
typeof controls(0) is TextBox -> tbox.Text = arr1(0)

2nd iteration:
i = 1
typeof controls(1) is Label -> do nothing

3nd iteration:
i = 2
typeof controls(2) is TextBox -> tbox.Text = arr1(2) OUT OF RANGE
EXCEPTION!

Do you understand your mistake? The index you use to loop through the
Controls collection must be separated from the one you use to access arr1.

Henri

[Leon]

Thanks so much Herni,
I got it:) You Have Been A Great Help!
And Thanks again!

"Henri" <hm********@hot mail.com> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

Ok, imagine that you have to simplify 1 textbox, 1 label, then 1 textbox
in
your Controls collection.
arr1's length should be 2 if it's the same as the number of textboxes.

Your code:

Dim I As Integer
For I = 0 To Me.Controls.Cou nt - 1
If (TypeOf Controls(I) Is TextBox) Then
Dim tbox As TextBox = CType(Controls( I), TextBox)
tbox.Text = arr1(I)
End If
Next

Let's trace the for...next loop in your code:

first iteration:
i = 0
typeof controls(0) is TextBox -> tbox.Text = arr1(0)

2nd iteration:
i = 1
typeof controls(1) is Label -> do nothing

3nd iteration:
i = 2
typeof controls(2) is TextBox -> tbox.Text = arr1(2) OUT OF RANGE
EXCEPTION!

Do you understand your mistake? The index you use to loop through the
Controls collection must be separated from the one you use to access arr1.

Henri

[Matt Berther]

Hello Henri,

Better yet (no type checking and casting, since the foreach can do this for
you)...

foreach (TextBox ctrl in Controls)
{
ctrl.Text = arr1[i];
i++;
}

--
Matt Berther
http://www.mattberther.com

Better:

Dim i As Integer = 0

For Each ctrl As Control In Controls

If TypeOf ctrl Is TextBox Then

DirectCast(ctrl , TextBox).Text = arr1(i)

i += 1

End If

Next

[Henri]

Hello Matt,

But what happens if Controls also contains controls different from TextBox?

Henri

"Matt Berther" <mb******@hotma il.com> a écrit dans le message de
news:On******** ******@TK2MSFTN GP09.phx.gbl...

Hello Henri,

Better yet (no type checking and casting, since the foreach can do this for you)...

foreach (TextBox ctrl in Controls)
{
ctrl.Text = arr1[i];
i++;
}

--
Matt Berther
http://www.mattberther.com

Better:

Dim i As Integer = 0

For Each ctrl As Control In Controls

If TypeOf ctrl Is TextBox Then

DirectCast(ctrl , TextBox).Text = arr1(i)

i += 1

End If

Next